UNC Knurled Thumb Screws — #6-32, 1/4"-20, 3/8-16, Aluminum, Colorful Hand Grip Knob Bolts

Match the thread size to your existing tapped hole or standoff. #6-32 UNC is the smallest of the three and is commonly used in PC cases, electronics enclosures, and light-duty DIY fixtures. 1/4"-20 UNC is the most widely used general-purpose inch thread in the US, found in camera tripods, woodworking jigs, and medium-duty assemblies. 3/8-16 UNC is a heavier thread used in larger fixtures, industrial equipment, and applications requiring greater clamping force. If you are unsure, measure the thread diameter of your existing fastener or check your equipment’s documentation.

The shank length should be long enough to pass through your panel or material and engage at least 1.5× the thread diameter of thread in the mating hole. For example, a 1/4"-20 screw (6.35mm diameter) generally needs at least 9–10mm of thread engagement for a secure hold. Shorter lengths (4–8mm) suit thin panels or shallow tapped holes; longer lengths (25–100mm) are used for thicker assemblies, stacked panels, or applications where the screw must pass through a spacer before reaching the threaded hole. When in doubt, choose a slightly longer length — excess thread can be accommodated with a nut or deeper hole.

These aluminum alloy thumb screws are designed for hand-tightened, tool-free applications where moderate panel retention or clamping force is needed — not for high-torque structural joints or load-bearing connections. For DIY enclosures, access panels, jigs, and fixtures, aluminum knurled thumb screws generally provide sufficient clamping force for secure, repeatable fastening. For higher-load or safety-critical applications, a steel or stainless steel thumb screw is typically recommended.

These screws are made from aluminum alloy with a color anodized or coated finish, which provides natural corrosion resistance for typical indoor use. They are not specifically rated for outdoor, marine, or high-humidity environments. For demanding outdoor or damp applications, a stainless steel thumb screw is generally the more suitable choice. These are optimized for indoor DIY projects, electronics enclosures, workshop fixtures, and camera/tripod accessories.

All three thread sizes use the UNC (Unified National Coarse) standard per ANSI/ASME B1.1. #6-32 fits standard #6-32 tapped holes and standoffs used in PC cases and electronics. 1/4"-20 fits standard 1/4"-20 tapped holes used in camera equipment, woodworking, and general hardware. 3/8-16 fits standard 3/8-16 tapped holes used in heavier fixtures and industrial equipment. Always verify the thread specification of your mating component before ordering to ensure compatibility.

Color is not a variant selector on this listing. After selecting your thread size/length and pack quantity, add a note in the order remarks field specifying your preferred color. If no color is specified, we will ship a standard color. Contact us before ordering if you need to confirm specific color availability for your chosen size and length.

The 1-pack is ideal for a single replacement or testing a size. The 2-pack suits paired fastener applications. The 5-pack covers a typical small enclosure or fixture build. The 10-pack is suited for larger projects, bulk replacement, or stocking multiple sizes. A 3-pack is available for select longer lengths. Buying in larger quantities generally offers a better per-unit value.